/*
 *  FILE: 
 *  	escape.c
 *
 *  DESCRIPTION:
 *  	Functions used to encode/decode %2F style requests, along with a function
 *      to encode a string into &#47; HTML encoded style.
 *
 *  FUNCTIONS:
 *  	hextochar()     -  Pass two hex values, both below or equal to "F".  Returns char for code.
 *  	html_escape()   -  Escapes plain text into a ``&#47;''style string.  (Escapes reserved HTML characters only.)
 *  	uri_unescape()  -  Unescapes ``%20'' style string into plain text.
 *  	uri_escape()    -  Escapes plain text into a ``%20'' style string. (Escapes reserved URL characters only.)
 *
 *
 * Copyright (c) 2004-2006 Karlan Thomas Mitchell<karlanmitchell@gmail.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *         This product includes software developed by
           Karlan Thomas Mitchell<karlanmitchell@gmail.com>
 * 4. Neither Karlan Thomas Mitchell nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY KARLAN THOMAS MITCHELL AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

 /*URI RESERVED CHARACTERS:
  * ';', '/', '?', ':', '@', '&', '=', '+', '$', ','
  */

/*  FROM: $OpenBSD: base64.c,v 1.3 1997/11/08 20:46:55 deraadt Exp $	*/
/*
 * Portions Copyright (c) 1996 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/*
 * Portions Copyright (c) 1995 by International Business Machines, Inc.
 *
 * International Business Machines, Inc. (hereinafter called IBM) grants
 * permission under its copyrights to use, copy, modify, and distribute this
 * Software with or without fee, provided that the above copyright notice and
 * all paragraphs of this notice appear in all copies, and that the name of IBM
 * not be used in connection with the marketing of any product incorporating
 * the Software or modifications thereof, without specific, written prior
 * permission.
 *
 * To the extent it has a right to do so, IBM grants an immunity from suit
 * under its patents, if any, for the use, sale or manufacture of products to
 * the extent that such products are used for performing Domain Name System
 * dynamic updates in TCP/IP networks by means of the Software.  No immunity is
 * granted for any product per se or for any other function of any product.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE.  IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL,
 * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN
 * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES.
 */

#include "encode.h"



 

/*This function works sometimes, i'm working on it...*/
char msdos_path(char * buffer, char * string, size_t buflen){
     size_t stringlen = strlen(string);
     size_t c = 0;
     size_t file_len = 0;
     char tbuffer[PATH_MAX];
     size_t tlen;
     tbuffer[0] = 0;
     buffer[0] = 0;
     
     while(c < stringlen && c < buflen - 1){
             if(string[c] == '\\'){
                         file_len = 0;
                         c++;
                         
                         tlen = strlen(tbuffer);
                         if(tlen > 8){
                                 tbuffer[6] = '~';
                                 tbuffer[7] = '1';
                                 tbuffer[8] = '\0';
                                 }
                         strlcat(buffer, tbuffer, buflen);
                         strlcat(buffer, "\\", buflen);
                         tbuffer[0] = 0;
                         continue;
                         }
             if(string[c] == '.'){
                         file_len = 0;
                         strlcat(buffer, tbuffer, buflen);
                         }
                         
             tbuffer[file_len] = string[c];
             tbuffer[file_len + 1] = 0;
                         
             c++;
             file_len++;
             }
             
     tlen = strlen(tbuffer);
     if(tlen > 8){
             tbuffer[5] = '~';
             tbuffer[6] = '1';
             tbuffer[7] = '\0';
             }
     strlcat(buffer, tbuffer, buflen);
             
     }
     


int base32_encode(char * buffer, size_t buffer_len, char * string, size_t string_len){
	*(buffer) = 0;

	char * pntr;
	char tbuf[20];
	size_t counter = 0;
	
	while(counter < string_len){
            sprintf(tbuf, "%02x", (unsigned char)string[counter]);
	    pntr = &tbuf[strlen(tbuf) - 2];
	    strlcat(buffer, pntr, buffer_len);
	    counter++;
        }

       return 0;
    }

int base32_decode(char * buffer, size_t buffer_len, char * string, size_t string_len){
	*(buffer) = 0;

	char firstc;
	char secondc;
	int counter = 0;
	int strc = 0;
	
	while(strc + 1 < string_len && counter < buffer_len){
       	    firstc  = string[strc];
       	    secondc = string[strc + 1];
	    buffer[counter] = hextochar(firstc, secondc);
	    strc += 2;
	    counter++;
        }

       return 0;
    }

int uri_to_base32(char * buffer, size_t buffer_len, char * string, size_t string_len){
	*(buffer) = 0;

	char tbuf[20];
	size_t counter = 0;
	
	while(counter < string_len){
	    if(string[counter] == '%'){
	      if(counter + 2 >= string_len)
		 break;
              sprintf(tbuf, "%c%c", string[counter + 1], string[counter + 2]);
	      counter += 2;
	      }
	    else
            	sprintf(tbuf, "%02x", (unsigned char)string[counter]);
	    strlcat(buffer, tbuf, buffer_len);
	    counter++;
        }

       return 0;
    }


char hextochar(char value1, char value2){
     char charHex[3] = {value1,
                        value2,
                        0}; /*can hold two values and a 0;*/
     return (char)strtol(charHex, NULL, 16);
     }




int html_escape(char * buffer, char * string, size_t buffer_len){
    printf("what?%c", buffer[0]);
    char * tbuf = (char *)malloc(6 * sizeof(char));  
    if(tbuf == NULL)
        return -1;
    
    while(*string){
    	switch(*string){
		/*Below are bad for some HTML stuff*/
		case '<':
		case '>':
		case '&':
		case '\"':
		case '\'':
		case ';':
		case ':':
		case '\n':
		case '\r':
			/*Add a "%", then add the escape hex code*/
			strlcat(buffer, "&#", buffer_len);
			snprintf(tbuf, 6, "%d;", *string);
			strlcat(buffer, tbuf, buffer_len);

			break;
		default:
			/*Just add the data, its ok..*/
			snprintf(tbuf, 6, "%c", *string);
			strlcat(buffer, tbuf, buffer_len);
			
	}
    	*string++;
    }
    

    free(tbuf);
    return 0;
}


int uri_unescape(char * buffer, char * string, size_t buffer_len){
    size_t string_len = strlen(string);
    
    if(string_len == 0 || buffer_len == 0){
	if(buffer_len > 0)
    		buffer[0] = 0;
	return -1;
	}


    size_t string_pos = 0;
    size_t buffer_pos = 0;


    char real_char;

    while ( string_pos < string_len && 
	     buffer_pos < buffer_len - 1){
	
	if(string[string_pos] == '%'){
		if(string_pos + 2 >= string_len)
			break;
		real_char = hextochar(string[string_pos + 1], string[string_pos + 2]);
		string_pos += 2;
	}
	else 
	 	real_char = string[string_pos];


	buffer[buffer_pos] = real_char;

	string_pos++;
	buffer_pos++;
	}

     buffer[buffer_pos] = 0;

/*	
    size_t posc;
    char tc[2] = {0,0};

    buffer[0] = 0;
    buffer[buffer_len - 1] = 0;
    for(posc = 0 ; posc < string_len  ; posc++){
	tc[0] = string[posc];
        if(tc[0] == '%'){
	    if(posc + 2 < string_len)
		tc[0] = hextochar(string[posc + 1], string[posc + 2]);
	    else
	    	buffer[posc] = 0; 
	    
	    posc += 2;/*Skip hex data*
        }
        buffer[posc] = tc[0];
    }
*/
    return 0;
}

size_t uri_escape_count(char * string, size_t str_len){
    size_t c = 0;
    while(c < str_len){
    	switch(*string){
		case ';':
		case '?':
		case '#':
		case ':':
		case '@':
		case '&':
		case '=':
		case '+':
		case '$':
		case '%':
		case ',':
		
		/*Below are bad for some HTML stuff*/
		case '<':
		case '>':
		case ' ':
		case '\"':
		case '\'':
		
		/*Special characters*/
		case '\0':
		case '\n':
		case '\r':
		case '\t':
		case '\b':

		 c++;
		 break;
	}
    	*string++;
    }
   return c;
}

int uri_escape(char * buffer, char * string, size_t buffer_len){
	return uri_escape_base(buffer, buffer_len, string, strlen(string));
	}

int uri_escape_base(char * buffer, size_t buffer_len, char * string, size_t string_len){
    buffer[0] = 0;
    char * tbuf = (char *)malloc(3 * sizeof(char));  
    if(tbuf == NULL)
        return -1;
    size_t string_count = 0;
    
    for( ; string_count < string_len ; string_count++ ){
    	switch(*string){
		case ';':
		case '?':
		case '#':
		case ':':
		case '@':
		case '&':
		case '=':
		case '+':
		case '$':
		case '%':
		case ',':
		
		/*Below are bad for some HTML stuff*/
		case '<':
		case '>':
		case ' ':
		case '\"':
		case '\'':
		
		/*Special characters*/
		case '\0':
		case '\n':
		case '\r':
		case '\t':
		case '\b':
			/*Add a "%", then add the escape hex code*/
			strlcat(buffer, "%", buffer_len);
			snprintf(tbuf, 3, "%x", (unsigned char)*string);

			/*Pad so we have a uniform to character padding*/
			if(strlen(tbuf) != 2)
				strlcat(buffer, "0", buffer_len);
			
			strlcat(buffer, tbuf, buffer_len);

			break;
		default:
			/*Just add the data, its ok..*/
			snprintf(tbuf, 3, "%c", *string);
			strlcat(buffer, tbuf, buffer_len);
			
	}
    	*string++;
    }
    

    free(tbuf);
    return 0;
}




#if !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP)


#define Assert(Cond) if (!(Cond)) abort()

static const char Base64[] =
	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static const char Pad64 = '=';

/* (From RFC1521 and draft-ietf-dnssec-secext-03.txt)
   The following encoding technique is taken from RFC 1521 by Borenstein
   and Freed.  It is reproduced here in a slightly edited form for
   convenience.

   A 65-character subset of US-ASCII is used, enabling 6 bits to be
   represented per printable character. (The extra 65th character, "=",
   is used to signify a special processing function.)

   The encoding process represents 24-bit groups of input bits as output
   strings of 4 encoded characters. Proceeding from left to right, a
   24-bit input group is formed by concatenating 3 8-bit input groups.
   These 24 bits are then treated as 4 concatenated 6-bit groups, each
   of which is translated into a single digit in the base64 alphabet.

   Each 6-bit group is used as an index into an array of 64 printable
   characters. The character referenced by the index is placed in the
   output string.

                         Table 1: The Base64 Alphabet

      Value Encoding  Value Encoding  Value Encoding  Value Encoding
          0 A            17 R            34 i            51 z
          1 B            18 S            35 j            52 0
          2 C            19 T            36 k            53 1
          3 D            20 U            37 l            54 2
          4 E            21 V            38 m            55 3
          5 F            22 W            39 n            56 4
          6 G            23 X            40 o            57 5
          7 H            24 Y            41 p            58 6
          8 I            25 Z            42 q            59 7
          9 J            26 a            43 r            60 8
         10 K            27 b            44 s            61 9
         11 L            28 c            45 t            62 +
         12 M            29 d            46 u            63 /
         13 N            30 e            47 v
         14 O            31 f            48 w         (pad) =
         15 P            32 g            49 x
         16 Q            33 h            50 y

   Special processing is performed if fewer than 24 bits are available
   at the end of the data being encoded.  A full encoding quantum is
   always completed at the end of a quantity.  When fewer than 24 input
   bits are available in an input group, zero bits are added (on the
   right) to form an integral number of 6-bit groups.  Padding at the
   end of the data is performed using the '=' character.

   Since all base64 input is an integral number of octets, only the
         -------------------------------------------------                       
   following cases can arise:
   
       (1) the final quantum of encoding input is an integral
           multiple of 24 bits; here, the final unit of encoded
	   output will be an integral multiple of 4 characters
	   with no "=" padding,
       (2) the final quantum of encoding input is exactly 8 bits;
           here, the final unit of encoded output will be two
	   characters followed by two "=" padding characters, or
       (3) the final quantum of encoding input is exactly 16 bits;
           here, the final unit of encoded output will be three
	   characters followed by one "=" padding character.
   */

int
b64_ntop(u_char const *src, size_t srclength, char *target, size_t targsize)
{
	size_t datalength = 0;
	u_char input[3];
	u_char output[4];
	int i;

	while (2 < srclength) {
		input[0] = *src++;
		input[1] = *src++;
		input[2] = *src++;
		srclength -= 3;

		output[0] = input[0] >> 2;
		output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
		output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
		output[3] = input[2] & 0x3f;
		Assert(output[0] < 64);
		Assert(output[1] < 64);
		Assert(output[2] < 64);
		Assert(output[3] < 64);

		if (datalength + 4 > targsize)
			return (-1);
		target[datalength++] = Base64[output[0]];
		target[datalength++] = Base64[output[1]];
		target[datalength++] = Base64[output[2]];
		target[datalength++] = Base64[output[3]];
	}
    
	/* Now we worry about padding. */
	if (0 != srclength) {
		/* Get what's left. */
		input[0] = input[1] = input[2] = '\0';
		for (i = 0; i < srclength; i++)
			input[i] = *src++;
	
		output[0] = input[0] >> 2;
		output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4);
		output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6);
		Assert(output[0] < 64);
		Assert(output[1] < 64);
		Assert(output[2] < 64);

		if (datalength + 4 > targsize)
			return (-1);
		target[datalength++] = Base64[output[0]];
		target[datalength++] = Base64[output[1]];
		if (srclength == 1)
			target[datalength++] = Pad64;
		else
			target[datalength++] = Base64[output[2]];
		target[datalength++] = Pad64;
	}
	if (datalength >= targsize)
		return (-1);
	target[datalength] = '\0';	/* Returned value doesn't count \0. */
	return (datalength);
}

/* skips all whitespace anywhere.
   converts characters, four at a time, starting at (or after)
   src from base - 64 numbers into three 8 bit bytes in the target area.
   it returns the number of data bytes stored at the target, or -1 on error.
 */

int
b64_pton(char const *src, u_char *target, size_t targsize)
{
	int tarindex, state, ch;
	char *pos;

	state = 0;
	tarindex = 0;

	while ((ch = *src++) != '\0') {
		if (isspace(ch))	/* Skip whitespace anywhere. */
			continue;

		if (ch == Pad64)
			break;

		pos = strchr(Base64, ch);
		if (pos == 0) 		/* A non-base64 character. */
			return (-1);

		switch (state) {
		case 0:
			if (target) {
				if (tarindex >= targsize)
					return (-1);
				target[tarindex] = (pos - Base64) << 2;
			}
			state = 1;
			break;
		case 1:
			if (target) {
				if (tarindex + 1 >= targsize)
					return (-1);
				target[tarindex]   |=  (pos - Base64) >> 4;
				target[tarindex+1]  = ((pos - Base64) & 0x0f)
							<< 4 ;
			}
			tarindex++;
			state = 2;
			break;
		case 2:
			if (target) {
				if (tarindex + 1 >= targsize)
					return (-1);
				target[tarindex]   |=  (pos - Base64) >> 2;
				target[tarindex+1]  = ((pos - Base64) & 0x03)
							<< 6;
			}
			tarindex++;
			state = 3;
			break;
		case 3:
			if (target) {
				if (tarindex >= targsize)
					return (-1);
				target[tarindex] |= (pos - Base64);
			}
			tarindex++;
			state = 0;
			break;
		}
	}

	/*
	 * We are done decoding Base-64 chars.  Let's see if we ended
	 * on a byte boundary, and/or with erroneous trailing characters.
	 */

	if (ch == Pad64) {		/* We got a pad char. */
		ch = *src++;		/* Skip it, get next. */
		switch (state) {
		case 0:		/* Invalid = in first position */
		case 1:		/* Invalid = in second position */
			return (-1);

		case 2:		/* Valid, means one byte of info */
			/* Skip any number of spaces. */
			for (; ch != '\0'; ch = *src++)
				if (!isspace(ch))
					break;
			/* Make sure there is another trailing = sign. */
			if (ch != Pad64)
				return (-1);
			ch = *src++;		/* Skip the = */
			/* Fall through to "single trailing =" case. */
			/* FALLTHROUGH */

		case 3:		/* Valid, means two bytes of info */
			/*
			 * We know this char is an =.  Is there anything but
			 * whitespace after it?
			 */
			for (; ch != '\0'; ch = *src++)
				if (!isspace(ch))
					return (-1);

			/*
			 * Now make sure for cases 2 and 3 that the "extra"
			 * bits that slopped past the last full byte were
			 * zeros.  If we don't check them, they become a
			 * subliminal channel.
			 */
			if (target && target[tarindex] != 0)
				return (-1);
		}
	} else {
		/*
		 * We ended by seeing the end of the string.  Make sure we
		 * have no partial bytes lying around.
		 */
		if (state != 0)
			return (-1);
	}

	return (tarindex);
}

#endif /* !defined(HAVE_B64_NTOP) && !defined(HAVE___B64_NTOP) */

